CMOS active pixel sensor using a pinned photo diode

ABSTRACT

Circuit architecture of an x-y addressable image sensor, in particular to that of a Complementary Metal Oxide Semiconductor (CMOS) active pixel sensor (APS). A substrate having an area divided into a plurality of pixel areas arranged in a series of rows and columns, having at least one control area separate from the pixel areas; a pinned photodiode formed in at least one of the pixel areas of the substrate; a readout transistor integrated on the pixel area of the substrate and operatively coupled to the pinned photodiode through a transfer gate and a charge to voltage converter; a row selection circuit having at least one selection transistor integrated on the substrate in the area for selecting the pixel area; a column selection circuit for selecting a group of pixels, the selection circuit formed in one of the control areas separate from the pixel areas, the selection circuit further comprising a column readout circuit including a double delta sampling circuit formed from a process that is compatible with CMOS technology; and a reset mechanism for resetting the floating diffusion. The present invention further comprises the use of overlapping gates to reduce the overall size requirements.

CROSS REFERENCE TO RELATED APPLICATION:

Reference is made to and priority claimed from U.S. ProvisionalApplication Serial No. 60/006,261, filed Nov. 7, 1995, entitled A CMOSACTIVE PIXEL SENSOR USING A PINNED PHOTODIODE.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of active pixel sensors,and more particularly to the architecture control circuits for activepixel sensors. More specifically, the invention relates to CMOS controlcircuits for active pixel sensors.

2. Description of the pior Art

Prior art active pixel sensors made from a CMOS process have usedsource/drain implants to form a photodiode, and polysilicon to formphotogates as the light sensing elements. These light sensing elementshave suffered from poor quantum efficiency, lag, and noise.

In order to overcome these problems, integration of a pinned photodiodein an active pixel sensor light sensing element was disclosed by Lee etal in U.S. Patent Application No. 08/421,173 to facilitate a pinnedphoto diode light sensing element within the architecture of an activepixel sensor. There is a shortcoming within this prior art device inthat it does not show the manner in which the pixels are controlled bythe control circuitry.

Prior art devices have numerous problems in integrating a camera systemon a chip using CMOS process technology. These problems include columnfixed pattern noise and the inability to fit the selection circuitrywith the corresponding output amplifiers into a desired pixel pitch.

As can be seen by the foregoing discussion, there remains a need withinthe art for a method and apparatus of incorporating a pinned photodiodebased image sensor within a CMOS device to alleviate fixed patternnoise, reduce the overall size of the device to achieve the desiredpixel pitch, and to provide for a means to compensate for thresholdvoltage variation.

SUMMARY OF THE INVENTION

The present invention is directed to overcoming one or more of theproblems set forth above. This invention relates to the circuitarchitecture of an x-y addressable image sensor, in particular to thatof a Complementary Metal Oxide Semiconductor (CMOS) active pixel sensor(APS) array. The invention describes elements of circuits and theirembodiments to operate an APS which has a Pinned Photo Diode as itsimage sensing element.

An active pixel sensor incorporating a pinned photo diode offersadvantages over conventional photogate or photodiode based APS by havinghigh quantum efficiency, low dark current, no image lag, and low resetnoise. This invention summary describes the circuitry building blocks,architecture, and circuit elements used in building this sensor.

Briefly summarized, one aspect of the present invention, describes anactive pixel sensor comprising: a substrate having an area divided intoa plurality of pixel areas arranged in a series of row and columns,having at least one control area separate from the pixel areas; a pinnedphotodiode formed in at least one of the pixel areas of the substrate; areadout transistor integrated on the pixel area of the substrate andoperatively coupled to the pinned photodiode through a transfer gate anda charge to voltage conversion means; at least one selection transistorintegrated on the substrate that is capable of selecting one row of thepixel areas; a column selection circuit capable of selecting a group ofpixels formed within the substrate in one of the control areas separatefrom the pixel areas, the selection circuit further comprising a columnreadout circuit including a double delta sampling circuit formed from aprocess that is compatible with CMOS technology; and a reset circuit.The present invention further comprises the use of overlapping gates toreduce the overall size requirements.

These and other aspects, objects, features, and advantages of thepresent invention will be more clearly understood and appreciated from areview of the following detailed description of the preferredembodiments and appended claims, and by reference to the accompanyingdrawings.

ADVANTAGEOUS EFFECT OF THE INVENTION

The present invention has the following advantages listed below:

Integrates the pinned photo diode light sensing element with specificcontrol and readout circuitry to improve noise and spectral responsecharacteristics;

Allows for integration of a camera system on a single chip using a CMOSprocess to provide reduced size and lower noise;

Provides a control and readout circuit having low noise with an activepixel sensor array having a pinned photodiode light sensing element; and

Improves the fixed pattern noise characteristics of a CMOS active pixelsensor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows the row and column addressing of a pixel array;

FIG. 2 shows a cross sectional view of eight transistors withoverlapping polysilicon used to form a NAND gate;

FIG. 3 shows a schematic of the column control logic of the presentinvention;

FIG. 4 shows a schematic of the row timing and control;

FIG. 5 shows a schematic of the row timing and control;

FIG. 6 shows a pinned photodiode APS pixel;

FIG. 7 shows a layout of the FIG. 6 schematic;

FIG. 8 shows a timing diagram of the operation; and

FIG. 9 shows a layer level diagram of the chip showing the layersincluding the lens and color filter array layers.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures.

DETAILED DESCRIPTION OF THE INVENTION

This invention relates to the circuit architecture of an x-y addressableimage sensor, in particular to that of a Complementary Metal OxideSemiconductor (CMOS) active pixel sensor (APS) array. An example pixelarray size of the present invention is 256×256 pixels and the overallchip size is 1.2×1.2 cm with a 40 pin pad frame. All of the row andcolumn circuitry is designed with a 40 μm pitch to match the pixel sizeusing a 2 micron design rule. The chip is designed to operate at 5 VoltCMOS voltage levels. Additional power supply voltages of 5, 2.5, and1.25 Volt Direct Current power supplies may be used to enhance theperformance.

Referring to FIG. 1, which is a block diagram of an active pixel sensoras envisioned by the present invention. The active pixel sensor 5comprises an array of pixels 10 that are arranged in rows and columns.The rows of the sensor 5 are provided with a global control logic block,generally referred to as row decoder 12 that has individual controlcircuits 22 for each of the rows within sensor 5. Global columnaddressing decoder 16 decodes column addresses for the column signalprocessing section 14 has individual control circuits 24 for each of thecolumns within sensor 5.

Referring to FIG. 2, the row and column addressing of the 256×256 pixelarray is preferably carried out using 8-input NAND gate 100, or thefunctional equivalent thereof. FIG. 2 shows the cross-section of the 8n-channel transistors 110-117 in series to form the 8-input NAND gate100. For row addressing, the inputs to n-channel transistors 110-117 aregenerally referred to as a0-a7, and for column addressing, the inputs tothe n-channel transistors 110-117 are generally referred to as b0-b7.

The eight series n-channel transistors 110-117 in the 8-input NAND gate100 were implemented using overlaid poly1-poly2 gates. As seen in FIG.2, there is a diffusion 120 between the third gate 112 and the fourthgate 113, as well as diffusion 122 between the sixth gate 115 andseventh gate 116. These gates having diffusions 120, 122 between themare separated by a spacing of 2 μm to allow room for the diffusions 120,122.

These transistors each have a gate length of 2 μm with 2 μm overlap ofthe poly1-poly2 gates of the adjacent transistors. Accordingly, the gateof transistor 110 overlaps gate 11 by 2 μm, for example. The center gate111 is overlapped by 2 μm on each side, by gates 110, 112. Thistransistor formation, including overlapping poly gates, is similar tothe formation that is used in charge coupled device (CCD) technology.

FIG. 2 shows the layout implementation of the 8 series n-channeltransistors 110-117 with overlapping gates for the 8-bit NAND gate 100.

The schematic of the column control logic which generates the columnselection signal SEL_(j) is shown in FIG. 3. The column selection signalis used with the crowbar signal to perform the fixed pattern noisereduction operation. The column control logic also controls the serialreadout of the data as will be explained.

Still referring to FIG. 3, a first bank of column selection transistors300 are connected to create a negative input OR gate. If any of thecolumn inputs (b₀ to b₇) are active (low), the corresponding transistorturns on and supplies V+ voltage to NAND gate 100. When all of theinputs b₀ to b₇ are inactive (high), an inactivity signal 302 isprovided. This inactivity signal 302 is buffered by buffer circuit 304and level adjusted and combined with the SEL signal by the levelshifting AND gate circuit 306 to form the selection signals SEL_(j),which are produced between pixel sampling interval. The SEL signal isused as described herein to reduce fixed pattern noise. OR gate 300preferably uses transistors having a width to length ratio of 9/2, and aNAND gate 100 having a width to length ratio of 22/2.

The column readout circuit is shown in FIG. 4. The elements within pixelregion 400, are contained in each pixel of the array. Included withinregion 400 are pinned photodiode 402, transfer gate 404, and floatingdiffusion 406. The photodiode used herein, is preferably a pinnedphotodiode 402 which yields improved blue response and without image lagproblems. The pinned photodiode 402 is preferably not overcoated bypolysilicon or other interconnect material, thereby enhancing blueresponse.

Also included within region 400 is reset transistor 410 which operatesto reset the floating diffusion 406 by clamping it to a zeroing voltageshown as V+. Source follower 412 receives and buffers the potential onfloating diffusion 406.

Row decoder transistor 414 is turned on to enable the voltage on sourcefollower 412 to be passed to the column processing circuitry.

The pinned photodiode 402 and the controlling devices, including gatesand transistors, are preferably made with any technology that iscompatible with CMOS, such as NMOS

Elements to the left of common chip region 420, and to the right ofregion 400 are the column circuitry 405 provided for each column ofpixels.

Column circuitry 405 includes stacked capacitors 422, each formed by aMOS capacitor 424 underneath a poly1-poly2 capacitor 426. This capacitorbank forms a high capacitance low kTC noise capacitor.

It is preferred that these devices also be made using a CMOS compatibleprocess. Column circuitry 405 is used as the sample and hold capacitorto increase the capacitance and reduce the kTC noise on this capacitor.

In operation, the reset level of the floating diffusion is first sampledduring any readout cycle by turning on the sample and hold resettransistor 430, to transfer the reset charge level on the floatingdiffusion to the reset capacitor bank 432. At the end of the lightintegration period, the photo-generated charge in the photodiode 402 istransferred by transfer gate 404 to floating diffusion 406. Thisphotocharge adds to the reset level already present in the floatingdiffusion 406. The total is sampled by turning on the sample and holdtransistor 434, thereby transferring the charge to capacitors 424 and426. Each reset level for each pixel is subtracted from each signallevel for the same pixel using off-chip circuitry. This correlation ofthe values effectively minimizes the Johnson noise within the pixel.

Crowbar switch 428 is used to reduce the fixed pattern noise byeffecting a clamped reset.

This process is called “double delta sampling” (DDS). The crowbar switch428 is activated at the same time the SEL signal is active, andselectively shorts the signal and reset level sample and hold capacitors424, 426 together to reduce the fixed pattern noise generated bythreshold voltage offsets in the p-channel column source followers. Thesignal and reset level of each pixel is read out, which allows foroff-chip correlated double sampling (CDS) to reduce noise generatedwithin each pixel

The crowbar 428 is then released, and the reset and sample values arerespectively applied to the capacitors 424, 426. Each of the sampledvalues that are applied to the capacitor effectively change the amountof charge on the capacitors. This change is measured. Since only thechange is important in this circuit, the absolute threshold variationsof the transistors are canceled out. This circuit and operation hencecancels the fixed pattern noise that would otherwise be generated bythreshold voltage offsets in the p-channel column source followers.

Circuits to the right of dashed line LL, indicated as region 420, arecommon to the entire chip. These circuits are readout transistor devicesand are also preferably CMOS compatible.

FIG. 5, seen in conjunction with FIGS. 1-4 and also with FIG. 6, showsthe schematic of the horizontal control logic. The horizontal controlsignals generated for the individual rows within sensor 5 are transfergate TX_(i), reset RST_(i), and row select ROW_(i). The voltage level ofthe TX_(i) and RST_(i) signals can be set independently of the rest ofthe logic circuits. To transfer charge accumulated beneath the pinnedphotodiode 402, the transfer gate 404 is clocked by TX_(i) to transferthe signal charge to the floating diffusion node 406. The high and lowlevels for the transfer gate are set using the V⁻TX and V⁺TX inputs tothe chip as shown in FIG. 5.

In a similar fashion the reset transistor 410 is driven by signal RSTi.The high and low levels for the reset transistor 410 are set using V-RSTand V⁺RST inputs to the chip. Since these gate thresholds can beadjusted, different effects and tolerances can be obtained. Thisadjustable gate threshold, for example, may make it possible to adjustfor charge capacity and antiblooming control tolerances, or providespecial effects in the acquired image. Buffer circuit 504 and levelshifting circuit 506 perform functions similar to the equivalentcircuits, 304 and 306, previously discussed in FIG. 3.

In addition, the reset level of the floating diffusion node 406 can beset using the input RSTLVL to the chip, which forms the value VDD thatis used as the reset.

The frame reset signal F-RST is an inverted signal (active low) thatwhen low switches on the reset transistors of the entire array, settingthe floating diffusion node to RSTLVL, but does not empty the signalcharge in the pinned photodiode.

FIG. 6 shows a potential energy diagram of a cross-section of the pixelregion 400 with the pinned photodiode 402, transfer gate 404, andfloating diffusion 406. In addition, each pixel region 400 containsreset, source follower input, and row selection transistors which arenot shown. Also shown is a potential energy diagram showing thecollection of photo-generated electrons in the pinned photo dioderegion.

The layout of the pixel region 400, as shown in FIG. 7 and viewed inconjunction with FIG. 6, has a pixel size of 40 μm×40. This pixel sizeis for the preferred embodiment disclosed, herein. It should be readilyapparent to those skilled in the art that other pixel sizes andconfigurations may equally apply the concepts of the present invention.The pixel overlaps the poly2 reset signal line with the poly1 rowselection line to maximize the optical fill factor. The L-shaped pinnedphotodiode region 402 is used to maximize the photoactive area. Theresultant optical fill factor is approximately 30%.

Anti-blooming is achieved by setting the transfer gate 404 and resettransistor 410 to a low level of 2.5 V to act as a lateral anti-bloomingdrain. A buried channel transfer gate is used to allow for completecharge transfer from the photodiode with a transfer gate high level of 5V.

The reset gate low level is set to 1.25 V so that charge levels beyondthis point will bleed off into the charge sink 606 (as shown in FIG. 6),which is biased at VDD. Hence, this acts as a lateral antibloomingdrain. A buried channel transfer gate 404 is used to allow for completecharge transfer from the pinned photodiode 402 with a transfer gate highlevel of 5 V. A threshold adjustment may be used to facilitate in chargetransfer to the floating diffusion.

The array is preferably read out one row at a time. The transfer gate404 transfers a row at a time. Each pinned photodiode 402, in the rowbeing transferred, transfers its stored charge to its respectivefloating diffusion 406. The reset and signal level from each pixel inthe selected row are loaded to sample and hold capacitors at the bottomof each column. The column selection transistors 300 provide that thedata from each column is then read out serially as pixel signal out 610.

The resultant voltage level timing diagram is shown in FIG. 8.Preferably, all clocks run at TTL levels. The high voltage level of thetransfer gate may need to be shifted to achieve complete transfer ofsignal charge from the pinned photodiode 402 to the floating diffusionnode 406.

Now referring to FIG. 8 in conjunction with FIG. 4, the operationproceeds as follows:

First, the reset transistor 410 is switched on at 800, setting thepotential of the floating diffusion node 406 to VDD; in this embodiment,approximately 3.5 V.

After the reset transistor 410 has completed its switching, the resetsample and hold transistor 430 is switched on at 802, storing the resetlevel of each pixel on the associated reset level sample and holdcapacitor bank 432.

Time 804 represents the end of the photo integration period. Transfergate 404 is pulsed to transfer the signal charge from the pinnedphotodiode 402 to the floating diffusion node 406.

The signal sample and hold transistor 434 is switched on at 806 to storethe signal level of each pixel on the signal level sample and holdcapacitor bank 430/432.

The column is then read out at 808 by switching on the clampingtransistors 442, 450 and storing the signal sample and reset levels ofthat column across the AC coupling sampling and reset capacitors 444,446.

Next, the clamped reset voltage is turned off, and the “crowbar” switch428 is turned on at 810. The clamped reset voltage Vcl, is controlled bylowering the voltage CL that drives the clamping transistors 442 and450. When crowbar switch 428 is turned on, the inputs to the p-channelsource-followers are shorted together. This averages the charge and alsocaptures the offset in the p-channel source followers in the columnbeing read out.

The final output signal is the signal level subtracted from the resetlevel.

Switching on the “crowbar” switch in the output circuitry suppresses theoffset in the p-channel column source-follower. The clamped reset and ACcoupling capacitors subtract out the offset from the p-channelsource-follower and minimizes the fixed pattern noise contribution.

FIG. 9 shows a layer diagram illustrating the substance 900, withphotodiode area 902. Two pixels, 910 and 920, are shown. Pixel 910 iscovered by a color filter layer 912 that passes only a single color oflight. Pixel 920 is covered by a different color filter 922. In this wayadjacent pixels receive information indicative of the light content ofdifferent colors. Each pixel is preferably covered by microlens 930,which refracts at least a portion of the incoming light to thephotodiode area 902.

The invention has been described with reference to a preferredembodiment; However, it will be appreciated that variations andmodifications can be effected by a person of ordinary skill in the artwithout departing from the scope of the invention.

PARTS LIST:

5 sensor

10 pixel array

12 row decoder

14 column signal processing

16 column addressing decoder

22 individual row control circuits

24 individual column control

100 8-input nand gate

110 nand gate input

111 nand gate input

112 nand gate input

113 nand gate input

114 nand gate input

115 nand gate input

116 nand gate input

117 nand gate input

120 diffusion

122 diffusion

300 column selection transistors

302 inactivity signal

304 buffer circuit

306 level shifting and gate

400 pixel region

402 pinned photodiode

404 transfer gate

405 column circuitry

406 floating diffusion

410 reset transistor

412 source follower

414 row decode transistor

420 common chip region

422 stacked capacitors (cs)

424 mos capacitor

426 polyl-poly2 capacitor

428 crowbar switch(cb)

430 sample and hold reset transistor

432 reset capacitor bank

434 sample and hold transistor

442 clamping transistor

444 sample capacitance (cos)

446 rest capacitance (cor)

450 clamping transistor

504 buffer circuit

506 level shifting and gate circuit

606 charge sink

610 pixel signal out

800 switch on period

802 sample and hold switch on

804 end of the photo integration period

806 signal sample and hold transistor on

808 selection transistors on

810 crowbar switch on

900 substance

902 photodiode area

910 pixel

912 color filter layer

920 pixel

922 color filter layer

930 microlens

SEL global select

RSTLVL reset level

SEL _(j) column select

SF source follower transistor

V+positive power supply

V−negative power supply

We claim:
 1. An active pixel sensor comprising: a substrate having an area divided into a plurality of pixel areas arranged in a series of rows and columns, having at least one control area separate from the pixel areas; a pinned photodiode formed in at least one of the pixel areas of the substrate; a readout transistor integrated on the pixel area of the substrate and operatively coupled to the pinned photodiode through a transfer gate and a charge to voltage conversion means; at least one row selection circuit integrated on the substrate that is capable of selecting one row of the pixel areas, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further includes a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR(NOR) function output; a column selection circuit capable of selecting a group of pixels formed within the substrate in one of the control areas separate from the pixel areas, the column selection circuit further comprising a column readout circuit allocated for each of the columns including a double delta sampling circuit formed from a process that is compatible with CMOS technology; and a reset circuit.
 2. The sensor of claim 1 wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid polysilicon levels 1 and 2 gates.
 3. The sensor of claim 1 wherein the column selection circuit further comprises at least one column selection circuit implemented with at least one stacked capacitor comprising: a MOS capacitor underneath a poly1-poly2 capacitor; and a crowbar switch incorporated into the column selection circuit.
 4. The sensor of claim 1 wherein the transfer gate off voltage level controls blooming levels.
 5. The sensor of claim 1 wherein the transfer gate on voltage (V+TX) setting completes charge transfer of the pinned photodiode.
 6. A sensor as in claim 4 wherein the reset level is controlled by a reset drain voltage control signal.
 7. A sensor as in claim 1 wherein pixel overlaps the poly-2 reset signal line with the poly-2 row selection line to maximize the optical fill factor.
 8. An active pixel sensor, comprising: a substrate having a plurality of pixel areas arranged in rows and columns, and at least one control area such that the control area is associated with at least one pixel. a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) functioon activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR (NOR) function output; at least one pixel area comprising: a) an optically active area including a printed photodiode, integrated on the substrate in the pixel area, and functioning to accumulate an indication of incoming photons therein; and b) an optically inactive area, including at least one readout transistor integrated on the substrate in the pixel area and operatively coupled to the pinned photodiode through a transfer gate; the readout transistor being formed of a formation process that is compatible with CMOS technology; and a plurality of correlated double sampling units within the pixel selection circuitry allocated such that there is a correlated double sampling unit for each of the columns.
 9. A sensor as in claim 8, wherein the pixel selection circuitry includes a plurality of transistors formed into a logical gate arrangement, the transistors having controlling gates overlapping other of the gates, the logical gates used for column addressing.
 10. A sensor as in claim 8 wherein the transistors in the pixel area have at least one overlapping gate.
 11. An active pixel sensor, comprising: a substrate having an area, the area functionally divided to form a plurality of pixel areas arranged in rows and columns; a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR (NOR) function output; each of the pixel areas comprising: a) a light information receiving element, integrated on the substrate in the pixel area, and functioning to accumulate an indication of incoming light therein; and b) control electronics, including at least one readout transistor element integrated on the substrate in the pixel area; the readout transistor element being formed of a formation process that is compatible with CMOS technology; and pixel selection circuitry elements, including a plurality of transistors having controlling gates, wherein at least one of the elements including gates on the substrate overlapping another of the gates on the substrate; and a correlated double unit allocated for each of the columns outside the pixel area.
 12. An active sensor as in claim 11, wherein the pixel selection circuitry elements include a plurality of transistors in series, at least one of the gates of one of the transistors having a part which overlaps at least a part of another gate of another transistor.
 13. An active sensor as in claim 11, wherein the pixel selection circuitry elements include a plurality of transistors in series, at least a first gate of a first of the transistors having a first part which overlaps at least a part of a second gate of a second transistor, and having a second part which overlaps at least a part of a third gate of a third transistor.
 14. An active sensor as in claim 11, wherein the light information receiving element is a pinned photodiode.
 15. An active sensor, comprising: substrate; at least one pixel area, formed in the substrate, and comprising: a) a light information receiving element, integrated on the substrate and functioning to accumulate an indication of incoming photons therein; and b) a control area, including at least one readout transistor element integrated on the substrate in the pixel area; wherein at least a portion of the light information receiving element overlapping and covering at least a portion of the control area; the light information receiving element formed of a formation process usually used for CCDs, and the readout transistor element being formed of a foundation process that is compatible with CMOS technology; a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR (NOR) function output; and a correlated double sampling unit allocated for each column.
 16. An active sensor as in claim 15 wherein the control area further includes a signal line including a control signal thereon, and wherein the light information receiving element covers at least a portion of the signal line.
 17. An active sensor as in claim 16 wherein the signal line is a reset line.
 18. An active sensor as in claim 17, wherein at least one of the elements includes a gate on the substrate overlapping another of the gates on the substrate.
 19. An active sensor as in claim 15 wherein the light information receiving element is a pinned photodiode.
 20. An active sensor, comprising: a substrate having an area, the area being functionally divided to form a plurality of pixel areas arranged in rows and columns, and at least one control area; each of the pixel areas comprising: a) a light information receiving element employing a pinned photodiode integrated on the substrate in the pixel area, and functioning to accumulate an indication of incoming photons therein; and b) control electronics, including at least one readout transistor element integrated on the substrate in the pixel area, and at least one selection circuit, the selection circuit comprising a plurality of transistors located adjacent one another, and wherein the transistors having gates on the substrate, at least one of the gates on the substrate overlapping another of the gates on the substrate; the readout transistor element being formed of a formation process that is compatible with CMOS technology; pixel selection circuitry elements, in the control area including a plurality of transistors having controlling gates, wherein at least one of the elements including gates on the substrate overlapping another of the gates on the substrate, and a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR (NOR) function output; and a correlated double sampling unit allocated for each of the columns.
 21. A mixed technology active pixel sensor, comprising: a substrate having an area, the area functionally divided to form a plurality of pixel areas arranged in rows and columns, and at least one control area separate from the pixel areas; a photodiode element integrated on the substrate in the pixel area, and functioning to accumulate an indication of incoming photons therein; at least one readout transistor integrated on the substrate in the pixel area; at least one selection transistor, integrated on the substrate in the pixel area to operate in selecting the pixel; the readout transistor, and the selection transistor being formed of a formation process that is compatible with CMOS technology; a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; a level shifting circuit having coupled to the OR (NOR) function output; and a column readout circuit formed in the control area including a double delta sampling circuit formed for each of the columns from a process that is compatible with CMOS technology.
 22. An active pixel sensor that provides correlated double sampling comprising: a substrate having an area functionally divided to form a plurality of pixels in a series of columns and rows, and at least one control area outside the area; a light information receiving element, integrated on the substrate in the pixel area functioning to accumulate an indication of incoming photons therein, coupled to a transfer gate having clocking means to adjust the voltage of the transfer gate; and at least one readout transistor element integrated on the substrate in the pixel area, and at least one selection circuit, the selection circuit comprising a plurality of transistors located adjacent one another, a sensing node, a switch, selectively operating to connect the sensing node to the readout transistor element, and a reset switch, operating to connect the sensing node to a reset level; a column readout circuit including a double delta sampling circuit formed from a process that is compatible with CMOS technology; pixel selection circuitry elements, including a plurality of transistors having controlling gates and a pixel selection circuit having at least one row selection circuit integrated on the substrate capable of selecting one row of pixels, the row selection circuit further comprising a boolean AND (NAND) function activated by a binary address indicative of the row in which the pixel resides, the NAND function being coupled to a OR (NOR) function, wherein the row selection circuit further comprises a series of transistors forming the boolean AND (NAND) function implemented using overlaid levels 1 and 2 polysilicon gates; and a level shifting circuit having coupled to the OR (NOR) function output.
 23. The sensor of claim 22 further comprising at least a first and a second chip input supplying a non-reset voltage, and a reset voltage to the control electronics.
 24. A sensor as in claim 23, wherein at least one of the elements including gates on the substrate overlapping another of the gates on the substrate. 